It is generally known that restaurants experience lost of flatware, i.e. eating and serving utensils (as knives, forks, and spoons), as a result of some of them being inadvertently discarded in garbage cans while discarding food wastes after meals. This may represent significant costs, so that many solutions have been provided in the prior art in attempt to detect and/or retain or separate such valuable articles, usually made of ferromagnetic or conductive metal, from the rest of the food wastes.
An example of a solution provided by the prior art involves trash can lids defining a circular inlet or funnel inlet provided with at least one metal detecting ring or coil to detect metal flatware passing nearby and emitting an alarm to prompt the user to recuperate the article(s) among the trash in the can. However, users are often not inclined to make the effort of finding and recuperating flatware articles once dropped in the can. Moreover, valueless metal objects such as aluminum foils used for wrapping food or as an intermediate liner in juice packs or napkin packs are detected and cause false alarms.
Another example involves a trash can cover defining a sloping chute plate provided with a magnet to attract and retain ferromagnetic flatware mixed in the food wastes being directed into the trash can. However, it is known that in actual use many of the flatware articles thrown in the can fall too fast or too far from the magnet to be effectively retained thereby so that many are nevertheless lost in the can. Moreover, certain valuable flatware articles among the most expensive, such as those being made of non-ferromagnetic stainless-steel or silver are not subject to magnetic attraction.
Other apparatuses provided with complex moving parts and actuators found in the prior art attempt to prevent detected flatware from being directed into a trash can by rapidly blocking an entry at the base of a chute to allow recuperation of the articles or deflecting the article(s) toward a receptacle for recuperation. However, in real applications, such mechanism do not prove to be reliable enough to deal with the speed of free falling or rapidly thrown metal objects and mechanical and electromagnetic interferences created by the surrounding mass of wastes.
Accordingly, there is a need for an apparatus and method for effectively detecting and recuperating metal objects mixed among wastes directed to a refuse container.